Batboard

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This forum is dedicated to helping people with questions about installing radio equipment in vehicles. This can include antenna installs, electrical wiring questions/problems, and mounting systems. Pictures of installs are welcome.

Note: Discussions regarding lighting, sirens, and other equipment now has its own forum in the 'off-topic' section below.

Looking around all I can really find is RF radiation from antennas mounted inside vehicles. That's not too much of a concern to me as I'll be mostly monitoring. My main question is what kind of loss is there by mounting the antenna inside vs on the trunk or roof? I'm trying to keep this as low-profile as possible because I don't want it to look like a cop car. 1 is UHF and the other is 7/800.

SUN-GARD’s top of the line, non-reflective, color-stable film will stand the test of time. Many car manufacturers are advising that metallized film may interfere with keyless locks, GPS and satellite radio systems. Shadow’s metal free construction makes it the perfect film to avoid signal disruption.

I have the antennas just sitting on the ends of the NMO cables now with no ground-plane and they're picking up signals pretty decently. I'm sure that partially answers my own question, but I wasn't sure if there was a general rule-of-thumb for or against it.

Don't laugh. I've had to put radomes on yagis and decorate them with flags so they meet the visual blight standards of a rooftop, and put white plastic cross arms on fiberglass sticks so they look like the crucifixes on Calvary (which actually turned out kind of cool looking). Those third grade skills suddenly came in handy.

Bill_G wrote:Don't laugh. I've had to put radomes on yagis and decorate them with flags so they meet the visual blight standards of a rooftop, and put white plastic cross arms on fiberglass sticks so they look like the crucifixes on Calvary (which actually turned out kind of cool looking). Those third grade skills suddenly came in handy.

I think I have a picture of your grade A skills somewhere then if thats the case...

Back on topic, one of the very small limo companies around here, they had radios installed in their 3-vehicle fleet, which was two limos and a towncar. The towncar was suposed to be the "supervisor car" so it had a MTS2000 convertacom installed in some werid spot by the back seats, but the quarter wave antenna for the covertacom was mounted upside down on U bracket by the back window.

I've 2 Stealth-Inside car antennas. Results were not so good. In one case the glass tint contains some metal which works to detune and attenuate the antenna. The other case had a matching network between the radio and the stealth antenna. The matching network couldn't maintain its tuning with temperature variations and the vehicle bouncing over pot holes plus the insertion loss. Transmit is most critical for a good match. Receive will be most affected by the signal to noise ratio. Best solution is to use a stealthy external antenna.